Issue #2793 improved error handling for packet extension

any exception thrown while parsing packets disconnects stream
changed to logging parsing problems and returning empty payload so we stay connected
added null check when sending to topic


Former-commit-id: 808727ce287116be8c8e2a93ce0fc4b3a996c0ef

cave/com.raytheon.uf.viz.collaboration.comm/src/com/raytheon/uf/viz/collaboration/comm/provider/SessionPayloadProvider.java

@@ -32,6 +32,8 @@ import org.xmlpull.v1.XmlPullParserException;
 
 import com.raytheon.uf.common.serialization.SerializationException;
 import com.raytheon.uf.common.serialization.SerializationUtil;
+import com.raytheon.uf.common.status.IUFStatusHandler;
+import com.raytheon.uf.common.status.UFStatus;
 import com.raytheon.uf.viz.collaboration.comm.identity.CollaborationException;
 import com.raytheon.uf.viz.collaboration.comm.provider.SessionPayload.PayloadType;
 
@@ -45,6 +47,7 @@ import com.raytheon.uf.viz.collaboration.comm.provider.SessionPayload.PayloadTyp
  * Date         Ticket#    Engineer    Description
  * ------------ ---------- ----------- --------------------------
  * Dec 16, 2013 2562       bclement     Initial creation
+ * Feb 12, 2014 2793       bclement     improved error handling
  * 
  * </pre>
  * 
@@ -54,6 +57,9 @@ import com.raytheon.uf.viz.collaboration.comm.provider.SessionPayload.PayloadTyp
 
 public class SessionPayloadProvider implements PacketExtensionProvider {
 
+    private static final IUFStatusHandler log = UFStatus
+            .getHandler(SessionPayloadProvider.class);
+
 
     /* (non-Javadoc)
      * @see org.jivesoftware.smack.provider.PacketExtensionProvider#parseExtension(org.xmlpull.v1.XmlPullParser)
@@ -61,6 +67,47 @@ public class SessionPayloadProvider implements PacketExtensionProvider {
     @Override
     public PacketExtension parseExtension(XmlPullParser parser)
             throws Exception {
+        try {
+            return parseInternal(parser);
+        } catch (CollaborationException e) {
+            // collaboration exceptions are only thrown for problems with our own format
+            log.error("Unable to parse collaboration packet", e);
+            return new SessionPayload(PayloadType.Command,
+                    SerializationMode.ISNULL, null);
+        } finally {
+            // ensure that we are at the end of the packet so we don't corrupt
+            // stream
+            while (!atEndOfPacket(parser)) {
+                parser.next();
+            }
+        }
+    }
+
+    /**
+     * @param parser
+     * @return true if parser is at the end tag of the payload packet
+     * @throws XmlPullParserException
+     */
+    private static boolean atEndOfPacket(XmlPullParser parser)
+            throws XmlPullParserException {
+        return parser.getEventType() == XmlPullParser.END_TAG
+                && parser.getName().equals(SessionPayload.ELEMENT_NAME);
+    }
+
+    /**
+     * Parse contents of packet extension from XMPP stream.
+     * 
+     * @param parser
+     * @return
+     * @throws CollaborationException
+     *             when error occurs with collaboration format
+     * @throws XmlPullParserException
+     *             when error occurs with XMPP stream
+     * @throws IOException
+     *             when error occurs with XMPP stream
+     */
+    private static PacketExtension parseInternal(XmlPullParser parser)
+            throws CollaborationException, XmlPullParserException, IOException {
         String typeString = parser.getAttributeValue(null,
                 SessionPayload.TYPE_ATTRIBUTE);
         String modeString = parser.getAttributeValue(null,
@@ -128,8 +175,7 @@ public class SessionPayloadProvider implements PacketExtensionProvider {
      * @throws JAXBException
      */
     private static Object unmarshalJaxb(XmlPullParser parser)
-            throws XmlPullParserException, IOException, CollaborationException,
-            JAXBException {
+            throws XmlPullParserException, IOException, CollaborationException {
         int tag = parser.next();
         if (tag != XmlPullParser.START_TAG) {
             throw new CollaborationException(
@@ -151,16 +197,14 @@ public class SessionPayloadProvider implements PacketExtensionProvider {
             throws XmlPullParserException, IOException {
         boolean done = false;
         StringBuilder payloadText = new StringBuilder();
-        int tag = parser.next();
         while (!done) {
-            if (tag == XmlPullParser.END_TAG
-                    && parser.getName().equals(SessionPayload.ELEMENT_NAME)) {
+            if (atEndOfPacket(parser)) {
                 done = true;
                 continue;
             } else if (parser.getEventType() == XmlPullParser.TEXT) {
                 payloadText.append(parser.getText());
             }
-            tag = parser.next();
+            parser.next();
         }
         return payloadText.toString();
     }

cave/com.raytheon.uf.viz.collaboration.comm/src/com/raytheon/uf/viz/collaboration/comm/provider/session/SharedDisplaySession.java

@@ -75,6 +75,7 @@ import com.raytheon.uf.viz.collaboration.comm.provider.user.VenueParticipant;
  * Jan 28, 2014 2698       bclement    removed venue info
  * Jan 30, 2014 2698       bclement    changed UserId to VenueParticipant
  *                                     changed args to create/configure venue
+ * Feb 12, 2014 2793       bclement    added additional null check to sendObjectToVenue
  * 
  * </pre>
  * 
@@ -171,6 +172,10 @@ public class SharedDisplaySession extends VenueSession implements
         if (obj == null) {
             return;
         }
+        if (topic == null) {
+            log.warn("Attempted to send object when topic not configured");
+            return;
+        }
         SessionPayload payload = new SessionPayload(PayloadType.Command, obj);
         topic.publish(new PayloadItem<SessionPayload>(payload));
     }